The present invention relates to an electromagnetic counter in which the display of character wheels cannot be intentionally changed.
As shown in the exploded perspective view of FIG. 8, an electromagnetic counter is composed of a count display device that includes character wheels 2, a driving device for operating said count display device, a driving source of said driving device, frame 1 which incorporates the above, and casing 5 for containing said frame 1. Reference numeral 50 indicates a window opened in the front surface of casing 5, reference numeral 51 indicates a lens embedded in said window 50, and reference numeral 53 indicates an opening in the back surface of casing 5 which is opened for mounting frame 1 inside casing 5. In addition, reference numeral 10b indicates a back wall that covers the back surface of frame 1.
The above-mentioned count display device is equipped with a plurality of character wheels 2, pinion mechanism 22 which rotates these character wheels 2, and drive gear 2a attached to the lowest digit character wheel of character wheels 2. Reference numeral 21 indicates the rotation shaft of character wheels 2, while reference numeral 23 indicates the rotation shaft of pinion mechanism 22.
The above-mentioned driving device is equipped with a reciprocating rocker 3, which is supported to be able to reciprocate while rocking and on which is formed a pair of operating claws 3a and 3b that engage with the above-mentioned drive gear 2a at their front ends, armature 31 provided on said reciprocating rocker 3, and coil spring 32 of said reciprocating rocker 3.
The above-mentioned driving source is equipped with coil 4, and roughly U-shaped magnetic current plate 42 attached to bobbin 41 around which the windings of coil 4 are wrapped. This magnetic current plate is composed of internal piece 42a, which is inserted into a slit formed in the center of said bobbin 41, and external piece 42b, which is positioned on the outside of said bobbin 41. The above-mentioned armature 31 is able to be oscillated corresponding to magnetic current generated in coil 4. In particular, this driving source is composed so as to be able to be inserted into and removed from frame 1 by means of insertion port 18 opened in the rear side wall of the above-mentioned frame 1. Reference numeral 41f indicates flanges provided on both ends of bobbin 41.
The following provides an explanation of the operating state of this electromagnetic counter. When electric current flows to coil 4, magnetic force is generated in magnetic current plate 42. Front end 31b and rear end 31a of armature 31 are attracted in the directions of external piece 42b and internal piece 42a, respectively, of magnetic current plate 42, and reciprocating rocker 3 rocks centering on rotation shaft 3c. As a result, operating claw 3b moves and pushes drive gear 2a causing drive gear 2a to rotate by the amount of half a gear tooth. At this time, coil spring 32, attached between the rear portion of reciprocating rocker 3 and frame 1, compresses as a result of being pushed by reciprocating rocker 3.
Next, when the current flowing to coil 4 is cut off, the magnetic force of magnetic current plate 42 lapses, and reciprocating rocker 3 rotates in reverse centering on rotation shaft 3 due to the force of coil spring 32. As a result, operating claw 3a works to cause drive gear 2a to rotate by an amount of half a gear tooth. Namely, as a result of turning the electric current supplied to coil 4 on and off one time, drive gear 2a rotates by the amount equal to one gear tooth, and the number of the lowest digit character wheel 2 provided on said drive gear 2a advances by one. When this operation is repeated, the rotation of said character wheel 2 is sequentially transmitted to the adjacent character wheel 2 of the next highest digit by means of pinion mechanism 22.
Examples of applications of this type of electromagnetic counter include coin counters used in arcade games and vending machines. The output end of a sensor switch installed in the coin pathway extending from the coin slot to the coin stacker is wired to this electromagnetic counter. When the sensor switch detects the passage of a coin, a pulse is sent to coil 4 of said electromagnetic counter. As a result, the numbers of character wheels 2 advance according to the number of coins. Coins that have passed by the sensor switch are contained in a coin stacker. Namely, since the number displayed by character wheels 2 of this electromagnetic counter agrees with the number of coins in said coin stacker, the amount of sales can be determined by reading the number displayed by character wheels 2.
As has been described above, frame 1, which incorporates a counter mechanism in the form of character wheels 2 and so forth, is mounted in casing 5. Although casing 5 and frame 1 are in close contact with each other, they are not adhered together. For example, as a result of projection 11, provided on the wall surface of frame 1 engaging with hole 52 provided in the wall surface of casing 5, it is possible to prevent frame 1 from coming out of casing 5. By using projection 11 in the shape of a wedge tilted towards the front as shown in FIG. 8, frame 1 can be smoothly mounted in casing 5, while simultaneously having the characteristic of both members being difficult to separate in spite of this smooth mounting.
However, since a thin sharp object such as a cutter knife can be inserted between casing 5 and frame 1 from the side of opening 53 in the back surface of casing 5, a gap can be formed, although only extremely slight, between said members. If projection 11 is then dislodged from hole 52 by this operation, frame 1 can be removed from casing 5 without destroying casing 5. Since character wheels 2 are exposed when casing 5 is removed, the numbers being displayed can be freely tampered with by performing this operation intentionally.
After the value displayed by character wheels 2 has been altered to a smaller value, coins equal to the difference between the amount after tampering and the original amount are removed from the coin stacker, and the value of character wheels 2 after tampering is made to agree with the number of coins in the coin stacker. Finally, casing 5 is again inserted into frame 1. When this is done, it becomes possible to obtain an illegal profit without this illegal operation being noticed by anyone.
The object of the present invention is therefore to provide an electromagnetic counter in which casing 5 cannot be removed from frame 1 so that the display of character wheels 2 cannot be intentionally tampered with.